New picropodophyllin analogs via palladium-catalyzed allylic alkylation-Hiyama cross-coupling sequences

A new approach for the synthesis of a new series of picropodophyllin analogs by using the palladium-catalyzed allylic alkylation-Hiyama cross-coupling sequences is discussed. An intramolecular aldol condensation and a stereoconvergent electrophilic aromatic substitution are shown to be the key steps that are involved in the process.